Landscape crops have decorated its surrounding landscape by being cultivated from spring to late fall. Recently, landscape crops are starting to get the limelight as crops that can be cultivated in large area farmlands. Therefore, we examined the growth characteristics of landscape crops, green manure yield and nitrogen production of crops that are cultivated during summer, which are sunflower, cosmos, sunnhemp and sesbania, in order to select crops that can be utilized as landscape crops and green manure crops. The height of landscape crops increased when the harvest time was later. Especially, sunnhemp, cosmos, sunflower and sorghum grew over 100cm. The days to flowering of sunnhemp and cosmos were 50 and 53 days each, and their flowering period of more than 50 days were long. The days to flowering of sunflower, which was 52 days, was short, and its flowering period, which was 21 days, was also short. When the harvest time was later, the green manure yield and nitrogen production of all crops increased. Individually, the green manure yield was higher in sunnhemp, sorghum, sunflower, with $7.2{sim}7.5Mg;ha^{-1}$, and was lowest in sesbania. The nitrogen production was higher in sunnhemp, with $168.1kg;ha^{-1}$ Therefore, as seen in its flowering characteristics, green manure yield and nitrogen production, sunnhemp had the best green manure and landscape effects among the landscape crops for summer.